A wireless communication system primarily uses a digital modulation scheme to more effectively use a limited frequency resource. A digital modulated signal may be subjected to a signal amplifying operation using a Radio Frequency (RF) power amplifier according to its usage, so that an amplified signal is delivered to an antenna.
A multi-carrier transmission scheme or a multi-dimensional modulation scheme may be used to concurrently transmit a great amount of information according to a user demand for high-speed and large-size data processing.
The RF power amplifier uses a battery power in an electronic device (e.g., a portable terminal) as a bias voltage. Thus, battery consumption caused by the RF power amplifier may be greater. Accordingly, a transmitter of the wireless communication system requires a power amplifier having a high-linear and high-efficiency characteristic. As an example of the power amplifier having the high-linear and high-efficiency characteristic, a power amplifier with a structure of Envelope Tracking (ET) and Envelope Elimination Restoration (EER) is used in general.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.